package demo1;

public class Computer {
    public void powerOn(){
        System.out.println("打开电脑");
    }
    public void powerOff(){
        System.out.println("关闭电脑");

    }
    public  void  useService(USB usb){
        usb.openDvice();
        if(usb instanceof Mouse){
            Mouse mouse=(Mouse) usb;
            mouse.click();

        }else if (usb instanceof KeyBoard){
            KeyBoard keyBoard=(KeyBoard) usb;
            keyBoard.input();
        }
        usb.closeDvice();
    }
}
